/***************************************************************************/
/*                                                                         */
/*  ttmtx.c                                                                */
/*                                                                         */
/*    Load the metrics tables common to TTF and OTF fonts (body).          */
/*                                                                         */
/*  Copyright 2006-2009, 2011-2012 by                                      */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_TRUETYPE_TAGS_H
#include "ttmtx.h"

#include "sferrors.h"


/*************************************************************************/
/*                                                                       */
/* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
/* messages during execution.                                            */
/*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_ttmtx


/*
 *  Unfortunately, we can't enable our memory optimizations if
 *  FT_CONFIG_OPTION_OLD_INTERNALS is defined.  This is because at least
 *  one rogue client (libXfont in the X.Org XServer) is directly accessing
 *  the metrics.
 */

/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_hmtx                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Load the `hmtx' or `vmtx' table into a face object.                */
/*                                                                       */
/* <Input>                                                               */
/*    face     :: A handle to the target face object.                    */
/*                                                                       */
/*    stream   :: The input stream.                                      */
/*                                                                       */
/*    vertical :: A boolean flag.  If set, load `vmtx'.                  */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
#ifndef FT_CONFIG_OPTION_OLD_INTERNALS

FT_LOCAL_DEF( FT_Error )
tt_face_load_hmtx( TT_Face face,
                   FT_Stream stream,
                   FT_Bool vertical )
{
    FT_Error error;
    FT_ULong tag, table_size;
    FT_ULong *ptable_offset;
    FT_ULong *ptable_size;


    if ( vertical )
    {
        tag = TTAG_vmtx;
        ptable_offset = &face->vert_metrics_offset;
        ptable_size = &face->vert_metrics_size;
    }
    else
    {
        tag = TTAG_hmtx;
        ptable_offset = &face->horz_metrics_offset;
        ptable_size = &face->horz_metrics_size;
    }

    error = face->goto_table( face, tag, stream, &table_size );
    if ( error )
    {
        goto Fail;
    }

    *ptable_size = table_size;
    *ptable_offset = FT_STREAM_POS( );

    Fail:
    return error;
}

#else /* !FT_CONFIG_OPTION_OLD_INTERNALS */

FT_LOCAL_DEF( FT_Error )
tt_face_load_hmtx( TT_Face    face,
                   FT_Stream  stream,
                   FT_Bool    vertical )
{
  FT_Error   error;
  FT_Memory  memory = stream->memory;

  FT_ULong   table_len;
  FT_Long    num_shorts, num_longs, num_shorts_checked;

  TT_LongMetrics*    longs;
  TT_ShortMetrics**  shorts;
  FT_Byte*           p;


  if ( vertical )
  {
    void*   lm = &face->vertical.long_metrics;
    void**  sm = &face->vertical.short_metrics;


    error = face->goto_table( face, TTAG_vmtx, stream, &table_len );
    if ( error )
      goto Fail;

    num_longs = face->vertical.number_Of_VMetrics;
    if ( (FT_ULong)num_longs > table_len / 4 )
      num_longs = (FT_Long)( table_len / 4 );

    face->vertical.number_Of_VMetrics = 0;

    longs  = (TT_LongMetrics*)lm;
    shorts = (TT_ShortMetrics**)sm;
  }
  else
  {
    void*   lm = &face->horizontal.long_metrics;
    void**  sm = &face->horizontal.short_metrics;


    error = face->goto_table( face, TTAG_hmtx, stream, &table_len );
    if ( error )
      goto Fail;

    num_longs = face->horizontal.number_Of_HMetrics;
    if ( (FT_ULong)num_longs > table_len / 4 )
      num_longs = (FT_Long)( table_len / 4 );

    face->horizontal.number_Of_HMetrics = 0;

    longs  = (TT_LongMetrics*)lm;
    shorts = (TT_ShortMetrics**)sm;
  }

  /* never trust derived values */

  num_shorts         = face->max_profile.numGlyphs - num_longs;
  num_shorts_checked = ( table_len - num_longs * 4L ) / 2;

  if ( num_shorts < 0 )
  {
    FT_TRACE0(( "tt_face_load_hmtx:"
                " %cmtx has more metrics than glyphs.\n",
                vertical ? 'v' : 'h' ));

    /* Adobe simply ignores this problem.  So we shall do the same. */
#if 0
    error = vertical ? SFNT_Err_Invalid_Vert_Metrics
                     : SFNT_Err_Invalid_Horiz_Metrics;
    goto Exit;
#else
    num_shorts = 0;
#endif
  }

  if ( FT_QNEW_ARRAY( *longs,  num_longs  ) ||
       FT_QNEW_ARRAY( *shorts, num_shorts ) )
    goto Fail;

  if ( FT_FRAME_ENTER( table_len ) )
    goto Fail;

  p = stream->cursor;

  {
    TT_LongMetrics  cur   = *longs;
    TT_LongMetrics  limit = cur + num_longs;


    for ( ; cur < limit; cur++ )
    {
      cur->advance = FT_NEXT_USHORT( p );
      cur->bearing = FT_NEXT_SHORT( p );
    }
  }

  /* do we have an inconsistent number of metric values? */
  {
    TT_ShortMetrics*  cur   = *shorts;
    TT_ShortMetrics*  limit = cur +
                              FT_MIN( num_shorts, num_shorts_checked );


    for ( ; cur < limit; cur++ )
      *cur = FT_NEXT_SHORT( p );

    /* We fill up the missing left side bearings with the     */
    /* last valid value.  Since this will occur for buggy CJK */
    /* fonts usually only, nothing serious will happen.       */
    if ( num_shorts > num_shorts_checked && num_shorts_checked > 0 )
    {
      FT_Short  val = (*shorts)[num_shorts_checked - 1];


      limit = *shorts + num_shorts;
      for ( ; cur < limit; cur++ )
        *cur = val;
    }
  }

  FT_FRAME_EXIT();

  if ( vertical )
    face->vertical.number_Of_VMetrics = (FT_UShort)num_longs;
  else
    face->horizontal.number_Of_HMetrics = (FT_UShort)num_longs;

Fail:
  return error;
}

#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_hhea                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Load the `hhea' or 'vhea' table into a face object.                */
/*                                                                       */
/* <Input>                                                               */
/*    face     :: A handle to the target face object.                    */
/*                                                                       */
/*    stream   :: The input stream.                                      */
/*                                                                       */
/*    vertical :: A boolean flag.  If set, load `vhea'.                  */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_hhea( TT_Face face,
                   FT_Stream stream,
                   FT_Bool vertical )
{
    FT_Error error;
    TT_HoriHeader *header;

    static const FT_Frame_Field metrics_header_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_HoriHeader

                    FT_FRAME_START( 36 ),
                    FT_FRAME_ULONG ( Version ),
                    FT_FRAME_SHORT ( Ascender ),
                    FT_FRAME_SHORT ( Descender ),
                    FT_FRAME_SHORT ( Line_Gap ),
                    FT_FRAME_USHORT( advance_Width_Max ),
                    FT_FRAME_SHORT ( min_Left_Side_Bearing ),
                    FT_FRAME_SHORT ( min_Right_Side_Bearing ),
                    FT_FRAME_SHORT ( xMax_Extent ),
                    FT_FRAME_SHORT ( caret_Slope_Rise ),
                    FT_FRAME_SHORT ( caret_Slope_Run ),
                    FT_FRAME_SHORT ( caret_Offset ),
                    FT_FRAME_SHORT ( Reserved[ 0 ] ),
                    FT_FRAME_SHORT ( Reserved[ 1 ] ),
                    FT_FRAME_SHORT ( Reserved[ 2 ] ),
                    FT_FRAME_SHORT ( Reserved[ 3 ] ),
                    FT_FRAME_SHORT ( metric_Data_Format ),
                    FT_FRAME_USHORT( number_Of_HMetrics ),
                    FT_FRAME_END
            };


    if ( vertical )
    {
        void *v = &face->vertical;


        error = face->goto_table( face, TTAG_vhea, stream, 0 );
        if ( error )
        {
            goto Fail;
        }

        header = ( TT_HoriHeader * ) v;
    }
    else
    {
        error = face->goto_table( face, TTAG_hhea, stream, 0 );
        if ( error )
        {
            goto Fail;
        }

        header = &face->horizontal;
    }

    if ( FT_STREAM_READ_FIELDS( metrics_header_fields, header ))
    {
        goto Fail;
    }

    FT_TRACE3(( "Ascender:          %5d\n", header->Ascender ));
    FT_TRACE3(( "Descender:         %5d\n", header->Descender ));
    FT_TRACE3(( "number_Of_Metrics: %5u\n", header->number_Of_HMetrics ));

    header->long_metrics = NULL;
    header->short_metrics = NULL;

    Fail:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_get_metrics                                                */
/*                                                                       */
/* <Description>                                                         */
/*    Returns the horizontal or vertical metrics in font units for a     */
/*    given glyph.  The metrics are the left side bearing (resp. top     */
/*    side bearing) and advance width (resp. advance height).            */
/*                                                                       */
/* <Input>                                                               */
/*    header  :: A pointer to either the horizontal or vertical metrics  */
/*               structure.                                              */
/*                                                                       */
/*    idx     :: The glyph index.                                        */
/*                                                                       */
/* <Output>                                                              */
/*    bearing :: The bearing, either left side or top side.              */
/*                                                                       */
/*    advance :: The advance width resp. advance height.                 */
/*                                                                       */
#ifndef FT_CONFIG_OPTION_OLD_INTERNALS

FT_LOCAL_DEF( FT_Error )
tt_face_get_metrics( TT_Face face,
                     FT_Bool vertical,
                     FT_UInt gindex,
                     FT_Short *abearing,
                     FT_UShort *aadvance )
{
    FT_Error error;
    FT_Stream stream = face->root.stream;
    TT_HoriHeader *header;
    FT_ULong table_pos, table_size, table_end;
    FT_UShort k;


    if ( vertical )
    {
        void *v = &face->vertical;


        header = ( TT_HoriHeader * ) v;
        table_pos = face->vert_metrics_offset;
        table_size = face->vert_metrics_size;
    }
    else
    {
        header = &face->horizontal;
        table_pos = face->horz_metrics_offset;
        table_size = face->horz_metrics_size;
    }

    table_end = table_pos + table_size;

    k = header->number_Of_HMetrics;

    if ( k > 0 )
    {
        if ( gindex < ( FT_UInt ) k )
        {
            table_pos += 4 * gindex;
            if ( table_pos + 4 > table_end )
            {
                goto NoData;
            }

            if ( FT_STREAM_SEEK( table_pos ) ||
                 FT_READ_USHORT( *aadvance ) ||
                 FT_READ_SHORT( *abearing ))
            {
                goto NoData;
            }
        }
        else
        {
            table_pos += 4 * ( k - 1 );
            if ( table_pos + 4 > table_end )
            {
                goto NoData;
            }

            if ( FT_STREAM_SEEK( table_pos ) ||
                 FT_READ_USHORT( *aadvance ))
            {
                goto NoData;
            }

            table_pos += 4 + 2 * ( gindex - k );
            if ( table_pos + 2 > table_end )
            {
                *abearing = 0;
            }
            else
            {
                if ( !FT_STREAM_SEEK( table_pos ))
                {
                    ( void ) FT_READ_SHORT( *abearing );
                }
            }
        }
    }
    else
    {
        NoData:
        *abearing = 0;
        *aadvance = 0;
    }

    return SFNT_Err_Ok;
}

#else /* !FT_CONFIG_OPTION_OLD_INTERNALS */

FT_LOCAL_DEF( FT_Error )
tt_face_get_metrics( TT_Face     face,
                     FT_Bool     vertical,
                     FT_UInt     gindex,
                     FT_Short*   abearing,
                     FT_UShort*  aadvance )
{
  void*           v = &face->vertical;
  void*           h = &face->horizontal;
  TT_HoriHeader*  header = vertical ? (TT_HoriHeader*)v
                                    : (TT_HoriHeader*)h;
  TT_LongMetrics  longs_m;
  FT_UShort       k = header->number_Of_HMetrics;


  if ( k == 0                                         ||
       !header->long_metrics                          ||
       gindex >= (FT_UInt)face->max_profile.numGlyphs )
  {
    *abearing = *aadvance = 0;
    return SFNT_Err_Ok;
  }

  if ( gindex < (FT_UInt)k )
  {
    longs_m   = (TT_LongMetrics)header->long_metrics + gindex;
    *abearing = longs_m->bearing;
    *aadvance = longs_m->advance;
  }
  else
  {
    *abearing = ((TT_ShortMetrics*)header->short_metrics)[gindex - k];
    *aadvance = ((TT_LongMetrics)header->long_metrics)[k - 1].advance;
  }

  return SFNT_Err_Ok;
}

#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */


/* END */
